Canadian’s spend approximately 80% to 90% of their time indoors. As the public recognizes the importance of healthy, comfortable and productive indoor environments, indoor air quality (IAQ) has emerged as a major concern. IAQ is a much talked about issue by both the general public and the building industry. The importance of IAQ cannot be underestimated. Indoor Air Quality in buildings can be affected by various factors including temperature, moisture and humidity, as well as biological and chemical contaminants. Biological contaminants include mould, bacteria, pollen, dander, dust mites, and other contaminants from building occupants. Mould is one of the most talked about issues associated with IAQ. The conditions that are necessary for mould growth include: moisture; oxygen; comfortable temperature (even below 0°C); and a food source (often cellulose-based).

Chemical contaminants include a wide range of compounds such as products of combustion and volatile organic compounds (VOCs), of which approximately 1,000 have been identified in the indoor air. These include chemicals such as formaldehyde, benzene and styrene. Common sources of VOCs found in indoor environments include paints, sealants, adhesives, composite wood products, ceiling tiles, flooring materials, carpet and carpet tile assemblies.

Suspended particulate matter, such as dust, dirt and fibres, are also contaminants that are a concern as these pollutants can be suspended in the air and can get into our lungs, potentially causing a variety of health and respiratory problems.

Some of the above criteria, if not managed properly, can lead to occupant discomfort while others can lead to a wide range of health problems including allergies, headaches, fatigue, respiratory problems, and chemical sensitivities.

Environmental hypersensitivity associated with indoor environments is becoming a more prevalent concern. Environmental hypersensitivity describes a range of adverse reactions including familiar ones like allergies and asthma and less familiar ones like chemical, light, temperature, sound and vibration sensitivity.

Hypersensitivity reactions occur when the immune system responds in an atypical manner to a typical exposure. The severity of hypersensitivity reactions varies considerable, with some people experiencing just annoying symptoms and some health threatening. Hypersensitivity and other illnesses associated with environmental exposures are increasing, therefore any cost effective changes in design and construction practices which can reduce exposures to substances of concern should be employed whenever possible. Due diligence demonstrated by designers and builders of a construction project may involve demonstrating that design details and specifications were used in a manner that exceeded common practice or code requirements.